viper's grass vs black salsify

viper's grass and black salsify both are nouns.

Word	Noun	Adjective	Verb	Adverb
viper's grass	Yes	No	No	No
black salsify	Yes	No	No	No

As nouns, viper's grass and black salsify are synonyms defined as:

viper's grass and black salsify: perennial south European herb having narrow entire leaves and solitary yellow flower heads and long black edible roots shaped like carrots

Other synonyms of viper's grass include scorzonera, Scorzonera hispanica.

viper's grass (noun)	black salsify (noun)
perennial south European herb having narrow entire leaves and solitary yellow flower heads and long black edible roots shaped like carrots	long black salsify
	perennial south European herb having narrow entire leaves and solitary yellow flower heads and long black edible roots shaped like carrots